test_runner: set mock timer's interval undefined

prevent adding timer to execution queue if clearInterval() called PR-URL: #59479 Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

Author: hotpineapple

lib/internal/test_runner/mock/mock_timers.js

@@ -328,6 +328,7 @@ class MockTimers {
  if (timer?.priorityQueuePosition !== undefined) {
  this.#executionQueue.removeAt(timer.priorityQueuePosition);
  timer.priorityQueuePosition = undefined;
+ timer.interval = undefined;
  }
  }
 

test/parallel/test-runner-mock-timers.js

@@ -201,6 +201,27 @@ describe('Mock Timers Test Suite', () => {
  // Should not throw
  });
  });
+
+ it('interval cleared inside callback should only fire once', (t) => {
+ t.mock.timers.enable();
+ const calls = [];
+
+ setInterval(() => {
+ calls.push('foo');
+ }, 10);
+ const timerId = setInterval(() => {
+ calls.push('bar');
+ clearInterval(timerId);
+ }, 10);
+
+ t.mock.timers.tick(10);
+ t.mock.timers.tick(10);
+
+ assert.deepStrictEqual(
+ calls,
+ ['foo', 'bar', 'foo'],
+ );
+ });
  });
 
  describe('globals/timers', () => {